1. Field of the Invention
The present invention relates to a hollow golf club head.
2. Description of the Related Art
In hollow golf club heads typified by a driver head, their volumes are increasing every year, so their crown portions and sole portions are getting thinner, and the areas of these crown and sole portions are increasing along with this trend. Hence, techniques for reducing the weights of golf club heads have been proposed (for example, Japanese Patent Laid-Open Nos. 9-99121 and 9-248353).
On the other hand, with an increase in head volume, a low-pitched impact sound is more likely to be generated at the time of striking a golf ball. Under the circumstance, golfers who prefer high-pitched impact sounds want golf club heads which generate higher-pitched impact sounds. As a strategy of increasing the pitch of an impact sound, a strategy of increasing the natural frequency of the head by providing a rib on the sole portion is available (for example, Japanese Patent Laid-Open No. 2011-62255).
As a method of forming a rib for adjusting an impact sound, as described above, it is possible to form a head and a rib as separate members and weld the rib to the sole portion of the head. However, because such a rib is normally a small component, it is troublesome to align and hold the sole portion and the rib in preparations for welding, leading to poor operating performance.